TP53 and neoplasm: Surprisingly, whereas there was no alteration in p53 expression in non-tumor BRAFV600E ATIIs, we observed a robust p53 induction in adenomas (Fig. 4E), thus suggesting that p21CIP1 activation in non-tumor ATIIs does not rely on p53 and that p53 induction in adenoma ATIIs does not promptly result in p21CIP1 expression.